Method of and apparatus for manufacturing incandescent lamps



' July 10, 19 23.

. H. D. MADDEN ET AL METHOD OF AND APPARATUS FOR MANUFACTURING INCANDBSCENT LAMPS Filed April 5, 1919 INVENTOIZS HAMYa/mmzw /ohw .313! w; 1923. mmxsa H. D. MADDEN ET AL METHOD OF AND APPARATUS FOR MANUFACTURING INCANDESCENT LAMPS Filed April 5, 1919 2 shesks Shet 2' 2. v Fly. 5.

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ATTORNEY.

are encountered if the wal Patented July 10, 1923.

1,461,155 earner caries,

HARRY ID; MADDEN, OF IBVINGTON, AND JOHN J. HIGGINS, 015 EAST ORANGE, NEW JERSEY, ASSIGNORS TO WESTINGHOUSE LAM? COMPANY, A CORPORATION OF PENNSYLVANIA.

METHOD OF AND APPARATUS FOR MANUFACTURING INCAN'DESCEN'J. LAMPS.

. Application filed. April 3, 1919. Serial No. 287,234.

1 '0 a] Z whom it may concern Be it known that we HARRY D. MADDEN, a citizen of the United states, and a resident of lrvin ton, in the county of Essex and State of ew Jersey, and JOHN J. HIGGINS, a citizen of the United States, and a resident of East Orange, in the county of Essex and State of New Jersey, have invented a new and useful Improvement in Methods of and Apparatus for Manufacturing Incandescent Lamps, of which the following is a specification.

This invention relates to the manufacture of incandescent electric lampsand, more particularly, to lamps ofthe so-called gaslilled type, and it has for its object the provision of a method of, and a machine for. exhausting and sealing-in lamp mounts in such manner as to eliminate a considerable number of separate operations heretofore considered necessary.

- According to the present practice of performing certain operations in the manufacture of incandescent lamps,'the bulb is first tubulate'd, the mount is then sealed within the bulb, and the sealed bulb is then exhausted and, if desired, an inert gaseous filling is introduced within the bulb, simultaneously with the exhausting operation. These several operations require special apparutus in the working of the glass parts involved and necessitate the performance ofa large number of sequential operations Which not only require expert operatives but occasion a considerable loss, due to defective lamp parts andcommonly termed shrmkage.

Furthermore, all operations performed with a'view to sealing-in the-lamp mount and exhausting the bulb are attended by the application of heat, which is something to be avoided as much as possible on account of strains produced in the glass by theheating andcooling of the same. I

Also, certain of the above mentioned operations have inherent manufacturing troubles which are a constant source of annoyance and would be avoided if the total vnumber of operations could be materially reduced. For example, in tubulating a bulb re arator to exhaustin glass troubles p p y l thicknem of the bulb varies beyond definite limits. This is something, therefore, that requires attention in the blowing of the bulbs, which might be disregarded if the lamp were exhausted cost of the lamp by a direct labor charge for accomplishing the same, but carries with it such cost items as materials used, investment in equipment, floor space, shrinkage and other overhead charges which must be taken into account in fixing the price of the finished lamp sold to the consumer. As a result of the invention, several of these cost items, if not eliminated, are considerably reduced.

According to the present invention the number. of operations for sealing-in and exhausting an incandescent lamp is reduced, which result is principally efi'ected by a change in the sequence of performing the operations and by doing agreater number thereof on a single machine. Briefly stated, the manufacturing steps included in our process and regarded as necessary to effect the consolidation of the mount with the bulb and to admit a gas filling, if desired,

after exhausting, are to suitably support the rnount within the bulb, regard being had for centering the same;. making a gas-tight seal at the neck of the bulb; applying heat to the exterior of the bulb for the purpose of'sealing-in the mount and assisting in the exhausting of air therefrom: introducing nitrogen or other inert gas; sealing-in and drawing down the mount, and annealing the glass parts previously subjected to heat.

Any machine, which will accomplish the objects contemplated by our invention by overcoming the manufacturing difiiculties above enumerated, mustembody means for performing the various process steps just recited and will be within the scope of the invention." r

sleeve 2.

' to like parts.

Throughout the several views of the drawings, similar reference characters refer In the accompanying drawings Fig. 1 is a sectional elevation of a machine head and associated apparatus for practicing ourinvention; Fig. 2 is a similar view showing, in detail, the bulb-supporting means and illustrating one of the steps performed in the sealing-in operation; Fig. 3 is a side elevation of a partially completed lamp and certain of the devices utilized in practicing our invention; Fig. 4 is a view similar to Fig. 3, illustrating a bulb and 1ts mount after having been drawn down, and Fig. 5 1s a,- plan view of cam members shown in rounding a portion'of the tube 5 is a sleeve 8 having a screw-threaded lower end constituting part of a stuffing box 9, and having, at its upper end, reduced portlons to receive parts to be hereinafter described.

A sleeve 10encloses the sleeve 8 and is provided with a feather 12 that engages a suitable ke way 12 formed in the bearing ounted adjacent to the upper end of the sleeve 10 is a gear Wheel 13 that is slidably secured, by means'of a su1table key 14, to the sleeve 8. The stufiing box 9 includes packing material that is confined 1n a recess in a collar 15 by the lowerend of the sleeve 8. The ends of the bearing sleeve 3 are provided with recesses conta1ning su1table packing material that is held therein by means of glands 16, 16 to constitute stuiiing boxes.

Bell-crank levers 17 and 18 are pivoted to a supporting block 11 by means of stud screws 19, 19. The arm 20 of the bell-crank lever 17 terminates in a bifurcated portion provided with studs or projecting portions adapted to fit a grooved collar 21 that is secured to the tube 5. The other arm 23 of the lever 17 has a roller 24 secured to its end in position to be actuated by a cam 25 having a plurality of cam surfaces as shown in Fig. 5 and hereinafter more fully deintegrally with, a gear casing 31, while its opposite end is attached to an operating rod 32.

The upper end of the rod 4 is bifurcated to receive the lower end of a member 33, the latter being pivotally mounted in the tube 5, and the former being provided with a pin '4 to engage a diagonal slot 33 in said member 33. A member 34v is pivotally mounted in the tube 5 in position to coop erate with the member 33, and its free end projects through a slot in the tube 5. The upper end of the member 33 and the adjacent lower end of the member 34 are provided with cooperating gripping edge surfaces which function in a manner to be hereinafter described.

Seated on the lowermost reduced portion of the sleeve 8 is block 35 having its opposite ends bifurcated to receive and pivotally support gripping members 36. The gripping members 36 are biased inwardly by helical springs 37 that are supported upon stud pins with which the sleeve 8 is provided. A collar 38 is located above the block 35 and is frictionally held upon the sleeve 8 to retain the block in position. A truncated rubber gasket 39 is forced over a shoulder 40 and is adapted to fit snugly between the shoulder and the collar 38. An asbestos collar 41, that is frictionally mounted on the opposite side of the collar 40, serves to prevent undue heating of the parts immediately below it.

The gear casing 31 is adapted to receive the gear wheel 13 and a pinion 42 which causes the gear wheel 13 to rotate by power transmitted through an enclosed gear wheel 43. A suitable cover plate '44 is provided for the teeth of the gear wheel 13. Upwardly extending rods 45 have their lower ends secured to the casing 31' and carry, at their upper ends, a rotatable bulb-supporting means comprising a gear housing 46, a

car wheel 47, and a cover plate 48. Bearmg balls 47 are interposed between the members 46' and 47 and the teeth of the latter mesh with those of a pinion 50, which is rotated synchronously with the pinion 42 by means of a connecting shaft 50 therebetween.

Supported on the housing 46 is a bulb holder 51 having five prongs or contact points so related'to one another as to support the bulb 61 in a vertical position, with its neck projecting downwardly. The lower portion of the neck of the bulb 61 is adapted to be heated by means of a burner 52, preferably annular in form and provided-with a plurality of nozzles 52 designed to intensity and localize the gas flames, as much as possible, upon a given portion of the neck of the bulb. The burner 52 is supported by a rod 53 fastened to the member 1 and is connectcd to a suitable supply of gas and air supporting and holdin by pipes, such as 49. A heat chamber or oven 54, having an annular burner muunted therein, is provided for heating the bulb, as is common in exhaust operations, The oven 54 is provided with suitable means for raising and lowering it in a vertical direction, and the lower portion thereof is slotted so that its lower edge may rest upon the upper surface of the burner a i It will be noted that the rod 4 may be independently reciprocated and may be maintained in-an upward position by means of a helical spring 56 held, under compression, in the bearing sleeve 3., A gas and a vacuum line 57 and 58, respectively, may be connected at this point by means of a connector 59 and a three-Way cock 60. Communication is established between the bulb 61 and the connector 59 by means of a longitudinal passage in the side of the rod 4, and illustrated in the drawing by a broken line. A key 22, carried by the rod 4, is adaptedto travel in keyways formed in the tube 5 and the sleeve 8 and functions to cause the said members to rotate in unison, and, at the same time to permit longitudinal reciprocation independently of each other. It will be noted that by means of the lever 29, the complete bulbmeans may be reciprocated independent y of the burners 52 and 55. This is possible since practically the entire supporting structure for the bulb is a unit capable of vertical or reciprocating movement by actuation of the lever 29. The contour of the cam 28 andthe length of the gear wheel 43' is such as to permit the desired 'movement to take tplace.

The operation 0 the machine may be described as follows: A mount 65 is first placed upon the reduced end portion of the tube 5, the flare of the mount abutting u on a suitable shoulder formed at this po nt on the tube. The leading-in wires 66 are inserted in the end of the tube 5 and are gripped between the jaws of members 33 and '34 which are opened by movin the rod 4 downwardly and are caused to c ose upon the leading-in wires by the upward movement of this rod, under the action of the spring 56. The rod 4 may be actuated in any suitable manner either automatically or manually.

On account of variations whlch are likely to occur in the internal diameters of the cylindrical portions of mounts, the lever member 34 is rovided, and its outward bias, pro

duced y the spring 56, functions to firmly hold the mount in position. The bulb 61 is next placed over the mount and is supported by the bulb holder 51. The rubber gasket 39 constitutes a gas-tight seal forthe mouth of the bulb which is engaged and held thereon by the gri ping members 36; The gas oven 54 ma .t en be drawn down, and heat the bulb 61 y the burner 55. Simultaneous ly, the intensity of the flames from the burnpleted in Fig, 2. The speed at which the below the seal there will beam or 52' may be increased from a mere pilot light to provide a suflicient temperature to render the'neck of the bulb plastic. 'Upon the application of the heat, the bulb and its 'mount are rotated by the mechanism previously described. During the application of the heat, the bulb, with its supporting means, is continuously rotated and slowly moved up and down by operation of the lever 29. This construction affords a satisfactory means of applying the heat over any desired area of the neck of the bulb 61 and partially assists in evacuating the bulb by causin I the air therein to expand.

As tie neck of the bulb to which the heat is applied gradually becomes plastic, the cam 28 may be rotated to produce an outward movement of the arm 27 and thereby effect a downward movement of the collar 15 and the sleeve 8, thereby causing a slight 85 pulling down of the bulb neck and. constricting' the ope'ning between the flared] portion of the mount and the wall of the bulb neck. This operation is shown as com- I cam members 25 and 28 are caused to rotate is very slow and ma be intermittent, if desired, the essential eature being the provision of suflicient intervals between the active surfaces to permit of the performance of certain operations between the functioning periods of thecams. At this stage, the bulb 61 isconnected to the vacuum line 58 and may be preliminarily exhausted, after which a filling. gas, such as nitrogen, argon, or the 1 0 like, maybe admitted through the line 57. This gas may then be exhausted andthe same gas admitted a second time. By repeating this operation, the air may be more completely exhausted and the purity of the admitted gas improved. It is obvious that, in a vacuum-type lamp,the exhausting'operation would consist of merel connecting the exhaust line to the bulb, and: by heating the bulb, a satisfactory commercial vacuum would be obtained.

After the gaseous filling has been introduced in the bulb 61, the sealing-in opera tion is completed by consolidating the flare of the mount 65 with the adjacent wall of 1 the bulb. In performing this operation, considerable care and skill are required'in applying the roper amount of heat to make the seal. e best results are obtained by so positioning the flames of the burner 52 that as much heat as-possible will be prevented from striking the portion ofthe glass above the point at which the seal is made, This may be partly accomplished by adjusting the flames to a fine point and eaus- 1 ing them" to strike immediately below the flared portion of the mount 65.

It will be seen that by applying the flame danger of atmospheric pressure collapsing the walls of an To promote success in the performing of the sealing-in operation, it is important that the internal pressure of the bulb shall be'substantially equal to the external or atcam 28, in a manner similar to that tube 5, through the medium of the cam' 25. v

mospheric pressure. In the case of a gasfilled lamp, the expansion of the gaseous filling, due to the heat applied to the exterior of the bulb. will increase the pressure thereof appreciably above what the pressure of the gas will be at normal temperature. It is obvious that, when there is a difference between the external and internal pressures the glass being in a plastic condition, which is necessary to make the seal between the mount and the bulb-difficulty may be encountered which will be manifested by either a blowing-out or a sucking-in of the glass that is plastic, depending upon whether the internal pressure is greater or less than the external pressure. It, therefore, follows that, in a vacuum-type lamp, the glass should be worked as cold as possible, and greater skill'is required in making the seal, but it is, in no sense, a physical impossibility, inasmuch as a skilled operator is capable of performing this step in the op eration of a machine for practicing our process.

The seal between the mount and the bulb is completed by a final operation of applying intense heat fora short period of time, accompanied by a further pulling down of the sleeve 8, which results in the removal of the cullet 68 as illustrated in .Fig. 3. The removal of the cullet may be effected by operating the bell-crank lever 18 through the agency of a second active surface on the previous'ly described. The cam 28 is effect ve in maintaining the parts controlled by the-bellcrank lever 18 in a way down position until the bell-crank lever 17 has had an opportunity of functioning by drawing down the This operation effects the pulling down of the mount 65, which is a standard operation performed by present methods of manufacturing for thepurpose of reinforcing the seal effected between the bulb and the mount, and is shown in Fig. 4 as having been performed.

From the foregoing description, it will be apparent that our invention has features for taking care of manufacturing problems which must-be overcome to make it a succase. We refer particularly to the desirabihty of maintaining the internal and-external pressures of 'a 'gas-filled lamp" a't'substantial equilibrium during' the making of the seal between "the mount and the bulb.

practicable to permit its being worked in order to avoid a sucking-in of thee-lass around the seal, due to'the external-atmospheric pressure; It' may be found'fadyisable to use any expedient which will have .a tendency to prevent any large area of the bulb neck from becoming heated to the stage of plasticity, as by regulating the fires to a hot point and adjusting the angle at which they are permitted to strike the glass. Similar precautions'will suggest themselves to those skilled in the art.

While we have herein shown and particularly described a preferred embodiment of our invention, we do not wish to be limited to the precise details of construction illustrated, as changes -may be readily made without departing from the spirit and scope of the invention.

lVhat is claimed is: l l

l. A step in the method of combining the exhausting and sealing-in operations in the manufacture of an incandescent lamp of the gas-filled type which consists in hermetically sealing said lamp by uniting the mount with the bulb while maintaining the internal and lexternal gas pressures substantially equa 2. The method of combining the exhausting and sealing-in operations in the manufacture of an incandescent lamp of the gas filled type, which comprises applying heat externally of the bulb and exhausting the air from within said bulb simultaneously therewith, introducing and maintaining a gas under pressure substantially equal to that of the surrounding atmosphere and si-' I multaneously therewith hermetically sealing iailrll) lamp by fusing the mount within the u Y 3. The method of combining-the exhausting and sealing-in operations in the manufacture of an incandescent lamp of the gasfilled type, which comprises applying heat externally of the bulb and exhausting the air simultaneously therewith, continuing the application of heat and intro'lucing an inert gas under pressure, partly produced by expansion under the influence of the heat,

until the external and'the internal pressures are substantially equal, and hermetically sealing the lamp by fusingthe mount within the bulb. e

4. The method of combining the exhausting and sealing-in operations in the manufacture of an incandescent lamp, which oomprises centrally supporting a mountwithin a bulb, making the mouth of the buIb gastight and exhausting the bulb therethrough memes sealing the lamp by fusing the mount and lit the bulb together.

5. The method of combining the exhausting and sealing-in operations in the manufacture of incandescent lamps, which com--' prises centrally supporting a mount within abulb, making the mouth. of the bulb gastight, applying heat upon the exterior of the bulb and simultaneously exhausting the same, introducing a gaseous filling under a pressure substantially equal to the atmospheric pressure, fusing the mount to the bulb and drawing down the mount while the seal is still. plastic.

6. The method of combining the exhausting and sealing-in operations in the manufacture of an incandescent lamp, which comprises centrally supporting a mount within a bulb, making the mouth of the bulb gas-tight, reducing the space between the v neck of the bulb and the flare of the mount by rendering. the former'plastic, exhausting the bulb' through said constricted opening, consolidating the mount with the bulb, and drawing-down the mount while the seal is still plastic.

7. The method of combining the exhausting and sealing-in operations in the manufacture of an incandescent lamp, which comprises centrally supporting a mount within a bulb, making the mouth of the bulbgastight, reducing the space between the neck of the bulb and the flare of the mount by rendering the former plastic, exhausting and introducing a gaseous filling through said constricted opening, equalizing the internal and external gas pressures upon the bulb partly by the application of heat, consolidating the mount with the bulb, and drawing down the mount while the seal is still lastic.

8. e method of combining the exhaust ing and sealing-in operations in the manufacture of an incandescent lamp, which comprises centrally supporting a mount within a bulb, securing the mount to its support by means of the leading-in wires. closing the mouth of the bulb with a gas-tight seal, gripping the bulb neck exteriorly of the seal, reducing the space between the neck of the bulb and the flare of the mount by rendering the former plastic and pulling it v, mouth of the bulb with a gas-tight seal,

gripping the bulb neck exteriorly of the seal, reducing the space between the neck of the bulb and the flare of the mount by rendering the former plastic and pulling it down while in this condition, exhausting and introducing a gaseous filling through said constricted opening, equalizing the internal and external gas pressure upon the bulb partly by the application of heat, consolidating the mount with the bulb, and drawing down the mount while the seal is still plastic.

10. The method of combining the exhausting and sealing-in operations in the manufacture'of an incandescent lamp, which comprises centrally supporting a mount within a bulb, making the mouth of the bulb gastight, applying heat at difi'erent areas of the bulb and simultaneously therewith synchronously rotating the bulb and the mount while independently reciprocating the bulb, relatively moving the heated areas of the bulb with respect to each other tc cause the bulb .to be constricted adj aoent its lower end, exhausting the bulb, filling the same with a gaseous atmosphere, fusing the mount withthe bulb and simultaneously therewith synchronously rotatingthe bulb and the mount while independently reciprocating the bulb, relativelymoving the heated areas of the bulb with respect to each other to constrict the bulb adjacent its mouth, exhausting the bulb through the neck and applving intense heat immediately below the fiare of the mount to fuse the mount to the bulb and hermetically seal the lamp.

12. The method of combining the exhausting and sealing-in operations in the manufacture of an incandescent lamp, which comprises centrally supporting a mount within a bulb, making the mouth of the bulb gastight, applying heat at different areas of the bulb and simultaneously therewith synchronously rotating the bulb and the mount while independently reciprocating the bulb, relatively moving the heated areas of the bulb with respect to each other to constrict the bulb adjacent its mouth, exhausting the bulb through the neck, applying intense heat immediately below the flare of themount to fuse the mount tothe bulb and hermetically seal. the lamp, and drawing down the mount.

13. The method of manufacturing tipless incandescent lamps which comprises exhausting the lamps through the neck of the the mouth of the bulb gas-' lillti are bulk and then sealing a mount within the nec 14. The method of manufacturing incandescent lamps, which comprises assembling a bulb and a mount, evacuating the bulb gniibthereafter sealing the mount within the 15.. The method of manufacturing incandescent lamps, which comprises assembling a bulb and a mount, evacuating the bulb, filling the bulb with an inert gas and thereafter sealing the mount within the bulb.

.16..The method of manufacturing incandescent lamps, which comprises assembling ,a bulb and a mount, evacuating the bulb and thereafter sealing the mount within the bulb and simultaneously hermetically sealing the lamp.

17. The method of manufacturing-incandescent lamps, which comprises assembling a bulb and a mount, evacuating the bulb, filling the bulb with an inert gas and thereafter sealing the mount within the bulb and simultaneously hermetically sealing the lamp.

18. The method of manufacturing incandescent lamps, which comprises assembling a bulb and a mount, evacuating the bulb through the neck thereof, and thereafter sealing the mount within the bulb.

19. The method of manufacturing incandescentlamps, which comprises assembling a bulb and a mount, evacuating the bulb,

through the neck thereof, thereafter sealing the mount within the bulb and'simultane. ously hermetically sealing the lamp.

20. The method of manufacturing incan descent lamps, which comprises assembling a bulb and a mount,-evacuating the bulb through the neck thereof, filling the .bulb with an inert gas, and thereafter sealing the mount within the bulb.

21.- The method of manufacturingincam descent lamps, which comprises assembling a bulb and a mount, evacuating the bulb through the neck thereof, filling the bulb with an inert gas, thereafter sealing the mount within the bulb and simultaneously hermetically sealing the lam I 22. The method of manuflicturin g incandescent lamps, which comprises assembling a bulb and a mount, heating the neck of the bulb relatively part of the bulb with respect to the mouth to cause the neck to beconstrictedadjacent the flare of the mount, evacuating the bulb while heating the same, and thereafter sealmg the mount within the bulb.

23. The method of manufacturing incan-L descent lamps, which comprises assembling a bulb and a. mount, heating the neck of the bulb, relatively moving the enlarged part of the bulb with respectto the mouth to' cause theneck tobe constricted adjacent theflare of the mount, evacuating the bulb while moving the enlarged heating the same, thereafter sealing the mount within the bulb and simultaneously neck of the bulb below the flare to seal the v mount within the bulb and to hermetically seal the lamp. i

25. The method of manufacturing an incandescent lamp, which comprises exhaust ing a bulb through the'neck and sealing a mount within the bulb by intense heating of the bulb immediately below the flare of the mount.

26. The method of manufacturing an incandescent lamp, which comprises exhausting a bulb through the neck, filling the bulb withan inert, gaseous atmosphere, and sealing a mount within the bulb by intense heating of the bulb immediately below the flare of the mount.

I 27. The method of making lamps free from tubulatures, comprising assembling a bulb and a mount, exhausting the air from within the bulb through the neck thereof and joining I the flare of the mount to the neck of the bulb.

'. 28. The method of forming tipless lamps,

.29. The method of making lamps free Y from tubulatures consisting of assemblingha bulb' and a mount, heating the neck of bulb adjacent the flare on the mount, forming a constriction therein adjacent the flare, creating a vacuum in the bulb b exhausting the air from within through e space between the flare and the constriction and applying heatto the neck of the bulb below the flare to cause the glass to roll or be drawn up and close the space between the I flare and the constriction in the neck of the bulb.

30. The combination in an incandescent lamp-making machine of means for exhausting a bulb and means operating subsequent 151 11 thereto'for sealing a mount within the b b. I v I 31. The combination in an incandescent lamp-making machine of meansfor supportj mg a bulb, means for supporting a mount, means for exhaustin said bu1b,'-and means operating ty to'said last named means for sealing the mount within said bulb.

32. The combination inv an incandescent lamp-making machine of means for exhausting a bulb, means for filling the bulb with a gaseous atmosphere, and means operating subsequently to said last mentioned means for sealing a mount Within-the bulb.

33. The combination in an incandescent lamp-making machine of means for support ing a bulb and means for supporting a mount, means for exhausting the bulb, means for filling said bulb with a gaseous atmosphere and means for sealing the mount Within said bulb, all of said means operating in the sequential order state 34. The combination in an incandescent lamp-making machine, of means for supporting a bulb, means for supporting a mount, means for rotating the bulb and the -mountin unison, means 'for heating said bulb and simultaneously there with exhausting the bulb, and means for fusing the mount to the bulb subsequent to the exhausting operation.

35. The combination in anincandescent lamp-making machine of means for supporting a bulb including means for making the neck of the bulb gas-tight, means for supporting a mount, means for heating the bulb adjacent its upper end, means for heating the bulb adjacent its mouth, meanslor ro-' tating the bulb and the mount during heat ing thereof, means for moving the upper and lower parts of-the bulb with respect to each other to produce a constriction in the neck of the bulb adjacent the mouth thereof, means for evacuating the bulb through the mount support and the neck of the bulb between the constriction and the flare of the mount, means for sealing the-mount within the bulb and means for drawing down the mount.

36. In a lamp-making machine the com bination of bulb-supporting means, mountsupporting means, means for rotating said bulb and'mount-supporting means in unison while permitting independent reciprocatorv movement therebe the bulb at difi'erent areas, means for neck- .subscribed our names this tween, means .for' heating pulling down the v 38. In a lamp-making machine, the combination of a. bulb-supporting means, a mount-supporting means, a seal for making the neck of the bulb gas-tight, means for rotating the bulb and the mount in unison, means for applying heat to the bulb at different areas, means for constricting the opening between the bulb neck and\ the mount, means for exhausting the bulb, means for completing the seal between the bulb and the mount, and means for drawing down the mount. 1

39. In a lamp-making machine, the combination of a bulb-supporting means, a

.mount-supporting means, a seal for making the neck of the bulb gas-tight, means for rotating the bulb and the mount in unison,

;means for applying heat to the bulb at different areas, means for constricting theopening between the bulb neck and the mount, means for exhausting the bulb, means for introducing a gaseous filling within the bulb, means for completing theseal between .the bulb and the mount, and means for drawing down the mount. a

40. A commercially unfinished incandescent electric lamp having a mount fused thereinand also being free from tips.

41. A commercially unfinished incandescent electric lamp having a mount fused therein and its exterior contour free from protuberances. I

In testimony whereof, we have hereunto of Ma rch, 1919.

- HARRY D. MADDEN.

JUHN J. HIGGINS.

twenty-sixth day- 

